Struct Attributes 

pub struct Attributes { /* private fields */ }

An ordered set of named, length-1 Arrow values.

Implementations

impl Attributes

pub fn new() -> Self

Empty attributes.

pub fn len(&self) -> usize

The number of attributes.

pub fn is_empty(&self) -> bool

True when there are no attributes.

pub fn get(&self, name: &str) -> Option<&ArrayRef>

The attribute value as a length-1 array.

pub fn contains(&self, name: &str) -> bool

True when attribute name exists.

pub fn get_str(&self, name: &str) -> Option<&str>

Convenience access for a string attribute.

pub fn get_primitive<T: ArrowPrimitiveType>( &self, name: &str, ) -> Option<T::Native>

Convenience access for a primitive attribute of type T.

pub fn insert(&mut self, name: impl Into<Arc<str>>, value: impl IntoScalar)

Insert or replace an attribute.

pub fn try_insert_array( &mut self, name: impl Into<Arc<str>>, value: ArrayRef, ) -> Result<()>

Insert or replace an attribute from an Arrow array of length 1.

pub fn with(self, name: impl Into<Arc<str>>, value: impl IntoScalar) -> Self

Builder form of Self::insert.

pub fn remove(&mut self, name: &str) -> Option<ArrayRef>

Remove attribute name and return its value.

pub fn iter(&self) -> impl Iterator<Item = (&str, &ArrayRef)>

The attributes in insertion order.

pub fn fields(&self) -> Fields

The attrs struct fields for these attributes. All fields are nullable.

pub fn from_struct_row(attrs: &StructArray, row: usize) -> Self

Read row row of an attrs struct. A null child value is an absent attribute.

pub fn union_fields<'a>( all: impl IntoIterator<Item = &'a Attributes>, ) -> Result<Fields>

The struct fields for the union of the keys in all. One key with two types is an error.

pub fn encode_rows( rows: &[Option<&Attributes>], fields: &Fields, ) -> Result<StructArray>

Encode one struct row per entry of rows, with fields from Self::union_fields. A missing key or a None row gives nulls.

Trait Implementations

impl Clone for Attributes

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Attributes

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Attributes

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for Attributes

fn eq(&self, other: &Self) -> bool

Equal when both hold the same keys with equal values, in any order.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.